Abstract

Step by Step Fabrication of Biomaterials based on Cell Adhesion Control

Kennedy Okeyo, Senior Lecturer, Institute for Frontier Life and Medical Sciences, Kyoto University

On-chip fabrication of biomaterials such as cell sheets based on self-assembly organization of cells into tissues continues to attract attention due to potential applications in regenerative medicine as well as in the development of in vitro models for drug screening. We recently developed a technique for step-by-step fabrication of cell sheets based on adhesion control. It involves minimization of cell-substrate interaction to initiate self-assembly of cells, not into spheroids, but into planar cell sheets which can be then overlaid or stacked into 3D tissue models. For cell adhesion minimization, we developed a mesh culture system where cells are seeded and grown on suspended ultra-thin (~2µm thick) mesh scaffolds consisting of considerably large apertures (exceeding 100 µm in size) and thin mesh lines (3-5 µm in width).

This talk will demonstrate the mechanics of cell sheet formation under this culture system, including control of cell orientation by mesh shape design, building of 3D tissues by overlay culture or direct stacking, and our recent attempt to initiate vascularization. In addition, the talk will touch on the potential application of the culture system to stem cell culture, with focus on the induction of differentiation of human iPS cells into trophoblast-like cell lineages capable of generating 3D cysts expressing trophoblast specific markers such as Cdx2 and secreting pregnancy hormones such as hCG hormone. Overall, the talk aims to demonstrate the potential application of our mesh-based culture technique to cell function manipulation and tissue engineering.